1. Field of the Invention
The present invention relates to a band sheet coiling tension applying apparatus in use for a slitter line for slitting a wide metallic sheet into multi slit band sheets, which the apparatus adjusts for correction a non-uniformity of tension generated when the slit band sheets are coiled following the slitting of the metallic sheet, to thereby uniformly apply a coiling tension to the slit band sheets without generating rubbed flaw on the surface of the slit band sheets, and endless belts for use with the band sheet coiling tension applying apparatus, and an endless belt Lubricant for the band sheet boiling tension applying apparatus.
2. Description of the Related Art
There is known a metallic band sheet or plastic sheet coiling tension applying band sheet coiling tension applying apparatus as disclosed in the specifications of Japanese patent Publication JP56-082755 A by the applicant of the present patent application (BELTBRIDELE, trade name) and Japanese patent No. 2651891 by the same applicant (ROBELTOR, trade name).
“Tension pads” of the felt pressing type are frequently used for coiling such a material that creates no problem when the surface of the band sheet suffers from rubbed flaw, patterns by impression or the like. The BELTBRIDLE apparatus with pulleys and endless belts, developed by the applicant of the present patent application, is used for coiling a glossy, plated material, stainless or nonferrous metal finished to high gloss.
In the BELTBRIDLE apparatus for a slitter line having the coil base material width of 5 feet, the number of endless belts used is about 100, and to tension the endless belts, about 200 number of pulleys are required.
The same number of parts as of those pulleys are assembled into the pulleys. Those parts are, for example, ball bearings to be installed to the center shafts of the pulleys, and intermediate spacer parts.
With the intention of eliminating the large number of pulleys, the applicant of the present patent application proposed the device for applying circular metallic strip with tensile force (Japanese Patent No. 2651891). In the patent, slit band sheets “a” are nipped with circular drums. The sheet pressing parts are linear in shape and narrow in area. Accordingly, in this patent, there is a limit increasing the generated tension. Further, there is a limit to the thickness of the band sheets to be passed (at present, it is limited to 2 mm or less). The patented technique cannot deal with the materials failing to satisfy such limitation requirements. For this reason, the BELTBRIDLE apparatus is reluctantly used for the band sheet coiling.
Also, in a general slitter line, coils having been subjected to high grade surface treatment and coils not having been subjected to such are both present. To deal with those coils of different grades, an equipment (of the combination type) equipped with the BELTBRIDELE apparatus and the tension pad, vertically arranged in the two stages, was developed by the applicant of the present patent application. In operation, the belt type function or the felt type function is selected in accordance with the grade of material to be processed.
In the device for applying circular metallic strip with tensile force (Japanese Patent No. 2651891), the endless belts are compressed between upper and lower pressure applying members each having a substantially complete round shape. The endless belts as drawn by the slit band sheets to be coiled are repeatedly subjected to deformations of compression and recovery. Intermolecular friction violently occurs in the belt material. As a result, the belts are greatly deteriorated by heat generation of the belts per se and their repetitive deformation of compression and recovery. A limit is put on the tolerable surface pressure of the endless belt under this condition. To handle the processed materials of a broad range of thickness values, a pressure receiving area of the belt, i.e., a pressing area of the belt corresponding to the sheet pressing part, must be large; otherwise, it is impossible to handle the band sheet of a large thickness. In this respect, the circular drum has a limit in its applications.
Thus, the device for applying circular metallic strip with tensile force (Japanese Patent No. 2651891) can handle limited kinds of processed materials. For this reason, the BELTBRIDELE apparatus is reluctantly used for the slitter line to slit those band sheets out of the limited kinds of band sheets. As described above, the BELTBRIDELE apparatus needs a number of purchased parts and manufacturing parts, and cost of assembling is high. This high cost of the BELTBRIDELE apparatus hinders the wide use of the belt type apparatus.
The BELTBRIDELE apparatus is such an apparatus that the upper and lower pressure applying members, which nip the band sheets, presses the pressing plates on both sides of the endless belt, and friction resistance thereat is utilized for the coiling tension for coiling the band sheets. At the pressing plate, friction heat is generated depending the amount of work. To remove the friction heat, the cooling water is circulated near the pressing plates. The friction heat is generated in the endless belts, and temperature rises in the belts per se. The heat transfers to the pulley side. When the BELTBRIDELE apparatus is continuously operated, the pulley is overheated. This leads to trouble of ball bearings assembled, and reduction of service life of the endless belts.
In the BELTBRIDELE apparatus, the endless belts are tensioned in a manner that the belts are stretched between a couple of pulleys located on both sides thereof, with the pressing plates and the frame structure being interposed therebetween. The endless belts are not guided over a range of about 500 mm at their mid parts. Accordingly, the endless belts are rotated while taking a course alternately to one side and to the other. In the work of coiling the slit, narrow band sheets, the band sheets take zig-zag courses (turns alternately to the right and left sides). As a result, the side edge of the band sheet coiled by the coiler is irregular in position.
Also, referring to a slitter line, the equipment includes upper and lower four stages of frames. Special coupling devices “b” are provided between the upper and lower frames in order to select a lift mode and to select a depressing state. Use of such coupling devices leads to a complexity of device construction and increase of device cost. There is a danger that a trouble of the coupling device “b” may cause an accident by falling of the upper and lower frames (see FIG. 39).